The present disclosure relates generally to light emitting diode (LED) assemblies and their applications.
LED has been used in different kinds of appliances in our daily life, such as traffic lights, car headlights, street lamps, computer indicators, flash lights, LCD backlight modules, and so on. The LED chips are produced by semiconductor manufacturing process in the front end, and then undergo LED packaging in the back end to result in LED assemblies or apparatuses.
LED packaging mainly provides mechanical, electrical, thermal, and optical supports to LED chips. LED chips, which are a kind of semiconductor products, are prone to degradation, or aging, if being exposed for a long time in an atmosphere full of humidity or chemical. Design for packaging white LEDs needs to further consider color temperature, color rendering index, phosphor, etc. The white LED could be provided by phosphor converting a portion of the blue light from a blue LED chip into green/yellow light such that the mixture of the lights is perceived as white light by human eyes. Because human eyes are vulnerable to high-intensity blue light, the blue light from a blue LED chip in a white LED package should not emit outward directly without its intensity being attenuated by phosphor. LED lighting apparatuses nowadays are power-saving but costly; hardly to attract common consumers to replace conventional lighting apparatuses. In order to make LED products more competitive in the market, LED package manufactures constantly pursue advanced packaging processes which are more reliable, low-cost, and high-yield.